Rendering order in the Built-in Render Pipeline

In the Built-in Render PipelineA series of operations that take the contents of a Scene, and displays them on a screen. Unity lets you choose from pre-built render pipelines, or write your own. More info
See in Glossary, the order in which Unity renders objects is based on two things: which render queue the object is in, and how Unity sorts objects within that render queue.

Render queues

Unity sorts objects into groups called render queues. Unity renders the contents of one render queue, and then renders the contents of another render queue, and so on.

Unity has the following named render queues, which it renders in the following order:

Name	Index	Description
Background	1000	Use this queue for anything that should be drawn in the background of your SceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info See in Glossary.
Geometry	2000	Use this queue for opaque geometry. This is the default queue.
AlphaTest	2450	Use this queue for alpha tested geometry. This is after the Geometry queue because it’s more efficient to render alpha-tested objects after all solid ones are drawn.
Transparent	3000	Use this queue for anything alpha-blended (shaders that don’t write to the depth buffer). Examples include glass, or particle effects.
Overlay	4000	Use this queue for effects that are rendered on top of everything else, such as lens flaresA component that simulates the effect of lights refracting inside a camera lens. Use a Lens Flare to represent very bright lights or add atmosphere to your scene. More info See in Glossary.

Note that SkyboxA special type of Material used to represent skies. Usually six-sided. More info
See in Glossary materials are a special case. Unity draws Skybox materials after all opaque geometry (after queue index 2500), but before all transparent geometry (before queue index 2501).

Setting the render queue

By default, Unity places objects in the render queue specified in their Unity shaderA program that runs on the GPU. More info
See in Glossary. You define this value using the [Queue] SubShader tag.

You can override this value on a per-material basis.

In the Unity Editor, you can do this in the material Inspector by setting the Render Queue property. In a C# script, you can do this by setting the value of Material.renderQueue using the Rendering.RenderQueue enum.

Sorting behaviors within render queues

Within each render queue, Unity sorts and draws objects based on their distance from the cameraA component which creates an image of a particular viewpoint in your scene. The output is either drawn to the screen or captured as a texture. More info
See in Glossary. The sorting behavior depends on the index of the render queue:

For queues with an index up to and including 2500 (Geometry + 500), Unity sorts Renderers in these queues using the behavior defined in OpaqueSortMode.FrontToBack by default.
For queues with an index of 2501 or above, Unity sorts Renderers in these queues using the behavior defined in TransparencySortMode.Default by default.

Setting the sorting behavior

How you change the sorting behavior within a render queue depends on the index of the render queue:

For queues with an index up to and including 2500 (Geometry + 500), you can change the opaque sort mode for a Camera by using the Camera.opaqueSortMode API.
For queues with an index of 2501 or above, you can change the default transparent sort mode by using the Rendering.GraphicsSettings-transparencySortMode API. You can change the transparent sort mode for a Camera by using the Camera.transparencySortMode API.

Vertex Lit Rendering Path

Extending the Built-in Render Pipeline with CommandBuffers